The present invention relates generally to railroad maintenance equipment, and more particularly to an apparatus that removes railroad ties. Railroad ties, which are conventionally made of wood, deteriorate over time due to weather and other factors, or the ties may become damaged for a variety of different reasons. Thus, it becomes necessary to periodically remove the deteriorated or damaged ties from the railroad track, and to replace them with new ties.
In the past, railroad ties have been removed by using various types of machines that were designed for such a purpose. Generally, the tie removal machines were built to roll on a railroad track and to stop at a rail tie that needed replacement. One type of such a machine, disclosed in U.S. Pat. No. 6,463,858 includes an extending member that positions a gripping device normally relative to the track and adjacent to an end of the rail tie to remove it. The gripping device has vice-like jaws that clamp onto the end of the rail tie. Then, the extending member extends away from the track (in a direction normal to the track), thereby removing the tie from the track.
One example of another type of such a removal machine is the Fairmont W-114-C Tie Shear Machine, manufactured by Fairmont Railway Motors (now part of the Harsco Corporation). In this type of machine, two spaced pairs of jaws are lowered upon the railroad tie, with one pair of jaws being positioned on the inside of each of the rails. The jaws of each pair are closed, thereby cutting the tie at two locations on the inside of the rails, such that the tie is divided into three parts—a center part and two outer end parts. Next, the jaws are raised, while remaining closed, thereby lifting the centerpiece out of the way, leaving the two outer end pieces below their associated rail. Next, the entire Tie Shear Machine is moved along the track, so that a kicker apparatus is positioned above the cut end pieces of the tie. The kicker apparatus, which includes a pair of kickers that can be extended outwardly, is activated to kick-out both outer end pieces from under their associated rail. Thus, all three pieces of the tie are removed by such a process, and the Tie Shear Machine may move on to the next tie to be removed, where the process is repeated.
Among the drawbacks of a machine such as the Fairmont Tie Shear Machine is that the entire machine must be accurately positioned twice for the removal of a single tie (i.e., once for the cutting and removal of the center piece of tie, and a second time for the removal of the two outer end pieces of tie). Such double movement for each tie is a waste of both the energy used to power the machine and the time of the operator and crew.